<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onMounted, onUnmounted, ref } from 'vue'
// import { PropType } from 'vue'
//vue3的语法
// defineProps({
//   slides: {
//     type: Array as PropType<BannerItem[]>,
//     required: true,
//   },
// })
//vue3+ts的语法
const {slides,autoplay = false,duration = 1000} = defineProps<{
  slides: BannerItem[]
  autoplay?:boolean
  duration?:number
}>()

//声明初始化值
let active = ref(0)

//上一张与下一张
const prev = ()=>{
    active.value--
    if (active.value < 0) {
      active.value = slides.length - 1  
    }
}

const next = ()=>{
    active.value++
    if (active.value > slides.length - 1) {
      active.value =  0
    }
}

let timer = -1
onMounted(()=>{
  start()
})
//当组件销毁时,关闭定时器
//vue2:descroyed()
onUnmounted(()=>{
    stop()
})
const stop =()=>{
     clearInterval(timer)
}
const start = () =>{
    if(!autoplay) return
      timer = window.setInterval(()=>{
        next()
    },duration)
}
</script>

<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="start">
    <ul class="carousel-body">
      <li class="carousel-item"
      :class="{fade:active===index}"
      v-for="(item,index) in slides" 
      :key="item.id">
        <RouterLink to="/">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="prev"
      ><i class="iconfont icon-angle-left"></i
    ></a>
    <a href="javascript:;" class="carousel-btn next" @click="next"
      ><i class="iconfont icon-angle-right"></i
    ></a>
    <div class="carousel-indicator">
       <span
         v-for="(item, index) in slides"
         :key="item.id"
         :class="{ active: active === index }"
         @click="active=index"
      ></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>